This invention relates generally to recuperators for furnaces, and more particularly to recuperators that are disposed within a furnace for utilizing the heat in the products of combustion to preheat the air before introducing the air into the burner for combustion.
There have been a few prior art proposals for recuperators for furnaces wherein the heat in the exhaust products of combustion is utilized to preheat the air used for combustion in the burner. However, with the increasing shortage and rising costs of various natural fuels, the desirability of using recuperators is increasing and the importance of such recuperators is increasing substantially.
The recuperators of the prior art have generally been located externally of the furnace and have utilized the exhaust products of combustion after they have been removed from the furnace. This has necessitated rather extensive insulation and also has resulted in structures which are difficult to mount and adequately seal, especially upon heating and cooling, and further, has made it difficult to properly meter the required amount of air to the burner. Thus while recuperators have had some limited success in a few specialized areas, they have not been generally successful in most fields of metallurgical furnaces.